Speaker and acoustic device using speaker

Abstract

In a frame, a diaphragm and an edge member are provided on a first side, and a magnetic driving portion having a magnetic circuit and a voice coil is provided on the second side. An edge support member is interposed between the edge accepting portion of the frame and the outer circumference fixing portion of the edge member. Part of the edge support member is a restricting portion extending toward the center of the frame. The restricting surface of the restricting portion faces the back of the edge member and diaphragm so as to be spaced with a distance.

What is claimed is: 
     
         1 . A speaker comprising:
 a frame;   a diaphragm,   an edge member disposed between the frame and an outer circumferential portion of the diaphragm, the edge member having a deformed portion close to a outer circumferential and a tapered position close to a center; and   a magnetic driving portion including a bobbin that is able to vibrate in a front-back direction, for causing the diaphragm to vibrate, the diaphragm being positioned on a first side along the front-back direction, the magnetic driving portion being positioned on a second side along the front-back direction;   wherein an edge support member is interposed and fixed between an edge accepting portion formed as part of the frame and an outer circumference fixing portion of the edge member, and a restricting portion extending inward beyond the edge accepting portion is formed as part of the edge support member;   wherein the restricting portion is positioned more on the second side along the front-back direction than the edge member and has a restricting surface that faces the edge member with a gap between the restricting portion and the edge member; and,   wherein a difference between an inclination angle α in a cross section of the diaphragm and the tapered portion of the edge member and an inclination angle β of the restricting surface of the edge support member is ±5 degrees or less.   
     
     
         2 . The speaker according to  claim 1 , wherein a vent extending from the first side to the second side is formed in the restricting portion. 
     
     
         3 . The speaker according to  claim 2 , wherein a groove open toward a center of the frame is formed in the restricting portion as the vent, and a plurality of grooves are circumferentially formed at intervals. 
     
     
         4 . The speaker according to  claim 1 , wherein an opposing wall facing an outer circumferential end face of the edge support member is provided as part of the frame. 
     
     
         5 . An acoustic device comprising the speaker of  claim 1 , wherein:
 the frame is fixed in a case; and,   an interior of the case is divided into an external ventilation space, which is located along the front-back direction more on the first side than the diaphragm, and a closed space, which is located along the front-back direction more on the second side than the diaphragm.   
     
     
         6 . The speaker according to  claim 1 , wherein the difference between the inclination angle α in the cross section of the diaphragm and the tapered portion of the edge member and the inclination angle β of the restricting surface of the edge support member is ±3 degrees or less. 
     
     
         7 . The speaker according to  claim 1 , wherein the restricting portion has a comb shape having many vents. 
     
     
         8 . The speaker according to  claim 7 , wherein each vent is a groove. 
     
     
         9 . The speaker according to  claim 8 , wherein the grooves are circumferentially arranged at a constant pitch. 
     
     
         10 . The speaker according to  claim 8 , wherein a main portion of the speaker has a true circular shape centered around a center line, and wherein an open end of each vent is open toward the center line.